Electric pulse counter apparatus

ABSTRACT

This invention pertains to the electrical circuitry for a counter apparatus which accepts a command number in the form of a sequence of digits in the usual manner, i.e., the most significant first, and then decrements from the command number down to zero, the circuitry comprising a plurality of cold cathode glow transfer tubes conventionally electrically connected in a left-to-right arrangement with a borrowing gate for each pair of adjacent tubes, including an inhibitor against borrowing during the loading of the tubes, only, and including further a gating distributor circuit for loading the tubes from left-toright with the last tube loaded being the units tube, and wherein the gating circuit to the units tube is left open after loading of the counter, the circuit including a pulse generator for generating a plurality of pulses transmitted through the gating circuit to the units tube for decrementing the tubes from the command number down to zero, at which time a signal is emitted from the apparatus, using the borrowing gate for decrementing purposes.

United States Patent 3,163,747 12/1964 Veverka Appl. No. Filed PatentedAssignee ELECTRIC PULSE COUNTER APPARATUS 5 Claims, 18 Drawing Figs.

US. Cl 235/92 PE,

235/92 AC, 235/92 CM Int. Cl. 03k 21/36 Field of 235/92 (21),92 (51),92(63),92 (29 FL) References Cited UNITED STATES PATENTS 6/1962 BagleyTIP! REIUDIR RJVUIL INPUTS Primary Examiner-Maynard R. Wilbur AssistantExaminer-Robert F. Gnuse Attorney-Henderson & Strom ABSTRACT: Thisinvention pertains to the electrical circuitry for a counter apparatuswhich accepts a command number in the form of a sequence of digits inthe usual manner, i.e., the most significant first, and then decrementsfrom the command number down to zero, the circuitry comprising aplurality of cold cathode glow transfer tubes conventionallyelectrically connected in a left-to-right arrangement with a borrowinggate for each pair of adjacent tubes, including an inhibitor againstborrowing during the loading of the tubes, only, and including further agating distributor circuit for loading the tubes from left-to-right withthe last tube loaded being the units tube, and wherein the gatingcircuit to the units tube is left open after loading of the counter, thecircuit including a pulse generator for generating a plurality of pulsestransmitted through the gating circuit to the units tube fordecrementing the tubes from the command number down to zero, at whichtime a signal is emitted from the apparatus, using the borrowing gatefor decrementing purposes.

PATENTED SEP28 I971 SHEET 0F 9 PATENTEU SEP2 8 ISYI SHEET 8 BF 9ELECTRIC PULSE COUNTER APPARATUS This is a divisional application ofcopending patent application Ser. No. 637 ,l53 entitled ELECTRICCIRCUITRY FOR AUTOMATIC DRAFTING MACHINE, filed May 9, 1967, is sued asU.S. Pat. No. 3,500,154 on Mar. 10, I970.

BACKGROUND OF THE INVENTION The electrical connection of a plurality ofcold cathode glow transfer tubes for counting purposes, whether positiveor negative mathematical incrementation, is not new. The manner andcircuitry for loading digits into such an arrangement of tubes. however,is believed novel as hereinafter presented. in that the usualarrangement is in one of three forms.

First. assuming a plurality of six cold cathode glow transfer tubesarranged in a left-to-ri'ght connection, and assuming it is desired toload a command number 321 into same, for example, the counting apparatuswould be loaded from the right tube, with the least significant, orunits, digit first. Thus the units digit, 1, would be loaded into therightmost tube, the tens digit, 2, next, and the hundreds digit, 3,would be loaded into the third tube from the right. This system has twodisadvantages: first, the person manually loading the tubes, orpreparing the data stream has to accomplish same backwards, and thus inan unnatural manner. Secondly, should one desire to read the number,whether from the beginning in loading same, or. on the tape, or whenloaded into the counting mechanism, the command number has to be readbackwards; again, an unnatural action.

A second approach is to always require a digit number to be loaded thathas the same number of digits as there are tubes.

Thus for a six tube arrangement, the command numeral 000321 would needto be loaded into this arrangement such that upon nonnal decrementation,only 321 pulses would be needed to decrement the command number to zero.This system requires the use and provision of additional characters inthe data stream and usually additional time in all respects except whenthe full digit capacity of the counter is utilized, as all tubes wouldrequire loading.

The third approach would be to provide circuitry wherein a shiftingtechnique is available, in which the first digit is loaded into therightmost tube. When an additional digit is sensed, all previous digitswould be shifted to the tube immediately left of the tube whereinpreviouslylocated, and the new digit would be located in the rightmosttube. This type of circuitry requires a complex arrangement foraccomplishing the electronic shifting.

SUMMARY OF THE INVENTION It is an object of this invention to provide acounter ap paratus wherein the apparatus will function to accept acommand number comprised of not more than a predetermined number ofdigits, wherein the number is loaded into the apparatus with the mostsignificant digit first, with the next-tothe most significant digitnext, etc., until the least significant digit, the units digit, isloaded last.

It is another object of this invention to provide a counter apparatuswherein only the exact number of digits which the command numberactually has is loaded into the apparatus.

Yet another object of this invention is to provide a counter apparatuswherein the units digit may be positioned in any tube, depending uponthe number of digits in the number being loaded, rather than alwaysbeing in the rightmost tube, with decrementation always taking placefrom the units tube containing the units digit.

Another object of this invention is to provide a counter circuit whereinthe shifting of a digit from one tube to another tube and the "circuitryfor accomplishing said shifting are rendered unnecessary.

It is another object of this invention to provide a counterapparatuscapable ofdctecting when the number loaded therein has beendecremented to zero.

Still another object of this invention is to provide a counter apparatuswherein the number which is loaded into the apparatus, or that numberwhich remains after certain decrementation thereof, is always directlyreadable.

Still another object of this invention is to provide a counter apparatuscapable of accomplishing the the aforementioned objectives, which isuncomplicated in circuitry, economical as to cost and parts, andeffective and rugged in service.

These and other objects of this invention will become more readilyapparent upon reference to the following description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a small perspective view ofan automatic drafting machine with which this invention is used, therear door thereof shown slightly ajar;

FIG. 2 is an enlarged plan view of the machine;

FIGS. 3 and- 4 are fragmentary elevational views of both doors, showingbanks of control circuits, as seen from the lines 3-3 and 3-4 in FIG. 2,respectively;

FIG. 5 is a side elevation view of the machine;

FIG. 6 is a sectional view as taken along the line 6-6 in FIG. 5, andshowing interior electric gear in schematic form;

FIG. 7 is an enlarged, fragmentary, perspective view of the drive andcontrol structure of the machine, certain parts broken away and othershown in section for clarity of illustration;

FIG. 8 is an enlarged plan view of the drafting pen carrier in relationto a drafting board, as taken on the lines 8-8 in FIG.

FIG. 9 is an enlarged plan view of the right side of the control panelof FIG. 2;

FIG. 10 is an enlarged plan view of the left side of the control panelof FIG. 2;

FIG. II is a schematic block diagram of the circuit of the presentinvention;

FIG. 12 is an embodiment of the Board 03 network for generating pulses;I

FIG. 13 is an embodiment of the Board 04 and Board 05 networks forrouting the numbers pulses to the counter;

FIGS. 14 and 15, when laid end-to-end with FIG. 14 on the left of FIG.15, shows an embodiment of the Board 02 network for directing thedirection signals to the correct translator and motor, and showing themultivibrator subcircuit which takes the place of the command signals;

FIG. 16 shows an embodiment of the Board 06 network for checking parityof the incoming automated or manual signals;

FIG. 17 shows an embodiment of the Board 01 network for decoding theincoming pulses; and

FIG. 18 is a foreshortened plan view of the eight level punched tapeusedby the present machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT The automatic drafting machineof this invention is indicated generally at 30 in FIGS. 1 and 2, withthe general schematic therefor indicated generally at 31 in FIG. 11. Themachine is housed by a pair of side panels 32 and 33, a front lowerpanel 34, left and right control panels 35 and 36 respectively, adrafting board panel 37, top panel 38, and bottom panel 39.

The rear of the housing comprises a pair of hinged door panels 41 and 42over a stationary rear base panel 43. On each door panel is mounted atrio of Boards, each Board comprising in the main a definable subcircuitas a part of the whole 31. Suffice it at this time to identify theBoards on door panel 41 as 03, 04, and 02 from top to bottom, and ondoor panel 42 as Boards 05, 01, and 06.

A punched tape reader 44 (FIG. I) mounted on one side of the machinehousing is provided for reading a conventional paper tape 45 (FIG. 18)having in this instance seven punch columns plus one column used for thetape transport sprocket. Within the base of the housing,'as shown inFIG. 6, the heavier electrical gear is mounted, the main part of thetape reader indicated at 46, the power supply at 47, a pair oftranslators at 48 and 49, and a counter at 51. To any power supply at47, a 117 v. AC current is converted to a DC current. This drives theother electronic equipment, which equipment reads a to-IS volt signalfed out from the tape reader 46, amplifying that to -24 v., and convertsthe signals to energize a pair of synchronous motors 52 and 53 (FIG. 7).

Operation of the motor 52 rotates by means of a worm gear 54 anantibacklash worm wheel 55 which in turn rotates a spline shaft 56extended completely across the machine on an X-axis The shaft 56 isrotatably mounted by a pair of supports 57and 58. Slidably mounted onthe shaft 56 is a wheel 59 which in turn is rotatably mounted on andcarries a slide block 61, adapted to horizontal movement as maintainedby a rollered connection at 62 with a guide track 63.

Mounted on and movable with the slide block 61 is an upright unit 64having a block 66 at its upper end supported on and movable across a rod67 secured to the machine housing. The drafting pen 68 for the draftingboard 69 (FIG. 8), drafting paper 70 shown in FIG. 1, is carried by acarrier unit 71 slidably mounted on the upright members 72 and 73 of theupright unit 64, and is controlled as to its movement by a pulley andcable unit, the cable 74 wrapped about the wheel 59.

Thus, in response to energization of the synchronous motor 52, that inresponse to actuation of the circuitry 31 (FIG. 11), the drafting pen ismoved upwardly and downwardly on a Y- axis. A solenoid 76 (FIG. 8) isprovided for raising and lower ing the pen 68 relative to the board 69,via a pivot arm 77, and with a floating arm 78 provided for maintainingfine control of the pen 68.

Operation of the other motor 53 also causes via a worm gear 79 and anantibacklash worm wheel 81 rotation of a hub 82. Another continuouscable 83 is connected, by a series of pulleys about which the cable isentrained, to both sides of the upper and lower slide blocks 61 and 66,wherein operation of the motor 53 results in reciprocal movement of theslide wheel 59, the blocks 61 and 66, the upright unit 64 and thedrafting pen carrier unit 71 mounted thereon. It is to be noted thatoperation of both motors 52 and 53 can therefore move the drafting pen68 in a direction other than on either an X or Y- axis.

Referring to FIGS. 16 and 18, the arrangement is such that either manualcommand inputs at 101 from the manual keyboard 102 (FIG. 9) can be putinto a Coding Block for transmission to a parity check of conventionalarrangement on Board 06, or the coded binary inputs from the tape reader44 (FIG. 1) can be forwarded to the parity check. From FIG. 9, where aplurality of push-return switches are shown, it is seen that eightdirection commands can be put into the Coding Block, namely 0 fordriving the pen 68 upwardly, A for driving the pen upwardly and to theright at 45, R for a straight right movement, D for right and down at45, I for for straight down, C for left and down at 45, L for straightleft, and B for left and up at 45. Digital number inputs of from 0through 9 are provided, with the other lettered switches calling forspecial auxiliary functions, such as setting the pen down on the board69, and traversing it while lifted.

A light for Parity Error Indicator is provided for visual notificationof same, and Manual Start and Stop buttons are provided. The Stop buttonenables the tape reader 44 to be stopped so that data may be insertedinto a drawing manually if desired.

On the left counter 35 (FIG. the six cold cathode glow transfer tubes103, 104, 105, 106, 107, and 108, representing the number 999,999 or anydivision thereof, reading from left to right, are shown. These tubes arespecified at a counting rate of 4,000 pulses per second and arecommercially available. Below the tubes, a Power On-Off switch is shownwith a voltage check meter 109 for all the system s voltages, theVoltage Selection kn'ob being shown. A valve 111 for turning on a Vacuumpump'(not shown) to place a vacuum on a certain area of the draftingboard 69 is provided.

The specific tubes 103-108, inclusive, used in this embodiment weremanufactured by Baird Atomic, Inc. of Cambridge, Massachusetts underdesignation GS IO/S. Each tube 103-108 was identical, and comprised adeci-stable device capable of transferring states, designated 0 through9, sequentially and cyclically from one state to the next lower stateupon receiving a pulse through line 166 leading to each respective tube,or from the borrowing gate in the counter 51 as described hereinafter.

Referring back to FIGS. 16 and 18, coded inputs 1, 2, 4, 8, A, B, C andD from the eight level tape 45 are shown coming into the Parity CheckBoard 06. A digit or a direction is coded in terms of a combination ofholes punched in the eight level tape 45, and is read by the reader 44into the Parity Check Board 06. If an odd number of holes 1, 3, S or 7are passed to the parity check Board 06, the signal is then passed on toBoard 01 (FIG. 17); if not, the Parity Error Indicator on the controlpanel 36 goes on, and a signal is sent by line 102 See FIG. 11) to aTape Reader control 113 to stop, via line 114. the Reader 44.

Upon a signal, 1 for example, being sent out from the Parity Check Board06, it is received at the Board 01, having been charged from a I5 v.pulse to a -24 v. pulse, where it is inverted by a transistor 116 foramplification purposes. The signal, as a pulse, is then split into twopaths, one a Not Signal out as 0 volt pulse, indicated by a bar over thenumber I. and the other as a Signal out,just 1, having been invertedagain by another transistor 117. There is an inverter circuit for eachof the seven levels of the tape 45, and wherein each inverter circuitproduces either a Signal Out or a Not Signal Out. The eight level D ofthe tape 45 is not used herein, but is available.

At the upper part of FIG. 17, an AND" gate is shown for passing thesignal L therethrough. Should a number command, such as 321, meaning 321increments it is desired the pen 68 move, be received by the DecodingBoard 01 (See FIG. 11), this command is sent directly via line 118 to aPulse Generating Board 03 (See FIG. 12), described hereinafter.Conversely, an AND gate 115 (FIG. 17) is provided for each direction andother commands, with a certain code therefor. For example, the code fortransmit ting an L" output signal from Board 01 is 1, 2, B, Z, andA,with the other commands having their own predetermined codes. Thus, byelectrically connecting the inverter channels with the "AND" gates ofBoard 01, directions are transmitted out on lines 119 (See FIGS. 11 and14) to the ROUTING BOARD 02 (FIGS. 14 and I5) and numbers aretransmitted on lines 118 to the PULSE GENERATING BOARD 03 (FIG. 12).

On Board 03 (FIG. 12) the first input signal, for example the digit 3for the command number 321, comes in on line 118a to the top side ofabistable multivibrator 121 of a string of bistable multivibratorsarranged to cascade down and trigger a number of pulses from the numberten down to the value of the digit put in, plus one for all nonzerodigits, or only one pulse for the digit zero. Thus, when the digit 3 wasput in, seven plus one or eight total pulses are triggered, with BSMV121 through 128 providing the eight pulses sent through lines 129-136 toline 137, and from there on line 138, the PULSE TRAIN OUTPUT Line, toBoard 04 (FIG. 13). The purpose for these pulses will be describedhereinafter.

Between each bistable is a delay 139, which delays passing the signal onto the next bistable for a few milliseconds. Next to the last bistableis a reset monostable 141 which, when tripped by the last pulse of thebistable circuit 128 sends a signal through lines 142, 143, 144, and alllines 146 to the lower side of each bistable to reset same for the nextdigit command to be put therein. Thus, the second command digit of 2will result in nine pulses out, and the third command digit of 1resulting in ten pulses out through line 138. The reset monostable 141also sends a pulse through lines 142 and 147 to Board 04 (FIG. 13) forresetting a bistable 148 (FIG. 13) to be in position to receive the nextcommand digit series of pulses, namely the digit 2. The digit 0,however, requires no pulses being transmitted on line 118 directly tothe bistable 128, with one pulse being sent out through line 137.

The first pulse of each group of pulses out of the Board 03 PulseGenerating circuit has a dual function, and shows the reason forproviding an extra pulse. It is forwarded through line 138 to Board 04,and also through line 149 to a clamping bistable 151 (P16. 15), whichenergizes a clamping relay 152 to change the position of four banks ofswitches 153, 154, 155, and 156 as illustrated. The importance of thiswill be seen hereinafter.

The first pulse to Board 04 (FIG. 13) enters on line 138, meets anormally closed Gage03, and passes through a normally open Gate 01 totrip a Bistable 01. The same pulse passes through line 157 and anormally open Gate 02 to a Three Stage Binary Counter DistributorCircuit 158. The Distributor Circuit 158 is a conventional binarycircuit comprising three bistables (not shown) making a three stagebinary counter for emitting A or I B orE, and C orgpulses depending uponthe number of input pulses. The first pulse into the Distributor Circuit158 is used to set up the circuit 158 to use the'remaining pulsesaccording to their digit command. Thus, as the left most tube 103 isalways set first, the first pulse com- .ing into the Distributor Circuitis set to result in an A, combination which then transmits a signal fromthe AND Gate 159 to open Gate 04.

At the same time that the Bistable 01 was tripped, and after Gate 02 hadpassed the first'pulse, the tripping resulted in closing Gate 02 andopening Gate 03 such that all succeeding pulses, seven for the digitthree, are then routed through lines 161 and 162 to the six Gates forthe six Counter tubes. As all gates are closed, but Gate 04, the pulsesare passed through line 163 to Gate 04, and line 164 to Board 05 whichcomprises six one-shot vacuum tube multivibrators (not shown) foramplifying the signal pulses to get a needed high voltage. The sevenpulses are then fed through line 166 to the cold cathode glow transfertube 103, with the to 9, 9 to 8, 8 to 7, 7 to 6, 6 to 5, to 4, and 4 to3 pulses stepping the glow in the tube backwards, all tubes having beenset initially at zero, setting thereby the number 3 into the left mosttube 103.

I The second digit 2, of the command number 321 changes the DistributorCircuit 158 to open Gate 05, and the third digit "1, both having passedthrough Board 03 in the same manner as the digit 3 causes Gate 06 toopen whereby the numbers 2 and l are set into the tubes 104 and 105,sequentially in the same manner as the digit 3. What has occurredtherefore is an electronic setting of the number 321 into the Counter51.

While the command digit pulses are being set into the tubes 103-108, itis necessary to prevent one tube, such as tube 104, from borrowing apulse from another, such as tube 103. The counter 51 includes an or"gate (not shown) electrically connected between each adjacent pair oftubes, utilized in its count down wherein the tube 104 does borrow fromtube 103, for example, in much the same manner as a mechanicalsubtracting machine. The left tube, 103 for example, is decremented byone upon the right tube, 104 for example, decrementing from state 0 tostate 9. To prevent, however, the tubes from borrowing during the pulseinput, the borrowing gate is grounded through line 165, changed switch156, and junction 229 (FIG. As will be seen hereinafter, the switch '156is returned to its illustrated condition during the count down of thecounter 51 such that the borrowing or" gate is no longer grounded.

When the first tube 103 was receiving its loading pulses, a signal fromthe line 166 was derived therefrom to be transmitted via line 167 to amonostable multivibrator control bistable 168 (FIG. 15) to create apotential via line 169, whereby a variable rate astable multivibratorpulse generator 171 is activated at approximately 100 pulses per second.At the same time, a signal is applied from control bistable 168 throughlines 264, 267, junction 268, line 172, and lines 173 to the right sideof a bistable 174 for each of the direction commands.

The signal generated by the pulse generator 171 is delivered by lines179, 181 and 182 to all of the upper gates 183, 184, 185, 186, 187, 188,189 and 190. It is also sent via line 191 to the high side of the pulserate control bistable 177, whereby the pulsing rate of the pulsegenerator 171 is slowly increased to 200 pulses per second, and whereinit can safely run as high as 300 pulses per second.

This safeguards the operation of the stepping synchronous motors 52 and53, and allows them to start up slowly from a standing stop, to alwaystrack and be synchronous with the pulse generator 171, whereby thestepping motors will not miss a single pulse, and will always match therate of the pulse generator 171. Another line 192 from the controlbistable 168 connects with a line 193 to the left junction 194 of switch154, but as the switch is in a N. 0. position due to energization of theclamping relay 152, that lead stops. The line 192 is also connected toline 196 which leads to lines 197 for the left side of each directionAND Gate 198, 199, 200, 201, 202, 203, 204 and 205.

When the direction L comes from Board 01 into Board 02, via a line 119,it is directed to an amplifier 206, there being an amplifier and anidentical emitter following circuit as illustrated for each directioncommand. From the amplifier 206, the signal is directed in two paths,one through an emitter follower 207, and one through a line 208 to theright side of the AND" Gate 198.

From the follower 207, the signal passes through a line 209, diode 211,line 212 to a junction 213 where it is prevented from backing into theGate 183 by a diode 214. lt passes on through lines 216 and 217 into aresistor network, in this case. resistances 218 and 219. Due to suchresistance, the signal goes to ground through junction 220, line 221,diode 222.

lines 223, 224 and 226 to the center terminal 227 ofthe switch 155. Asthe relay 152 had been activated by a pulse from pulse generating Board03 having been placed into the bistable 151. the switch 155 is closed toground through the line 228 and junction 229.

The resistance 218, however, permits a signal to be sent from line 217through junction 231, line 232, diode 233, lines 234 and 236 to ajunction 237 and line 238 leading to the clamping bistable 151, thusunclamping it and returning the switches 153-156 to their illustratedconditions.

Returning to the L" AND Gate 198, with the pulse generator 171 working,both the control bistable 168 signal and the direction signal 208 arepresent at the Gate 198, which therefore produces an output through line239 which trips the bistable 174, producing thereby an output throughline 241 to open the Gate 183, whereby all pulses being generated by thepulse generator 171 flow through the Gate 183 and diode 214 to line 216.It should be noted here that the first pulse through line 241, due to anumbers command followed by a direction command being received at theGate 198, is directed from junction 242, diode 243, line 244, junction246, and line 247 (See FlG. 11) to the Tape Reader Control 113, wherebythe Tape Reader 44 is stopped.

The pulses through line 216, generated by the pulse generator 171 arethen transmitted through the resistances 218 and 219 to an appropriateTranslator, in this case 48 for the X- axis. Each Translator is designedfor use with its respective synchronous motor, and is designated to stepthe motor so as to provide an incremental pen movement of 0.002 inch perpulse. As the pulses are transmitted through line 248 to energize themotor 53, they are also fed as signals through a junction 249, line 251,diode 252, line 253, junction 254, line 256, terminal 257 of switch 153,through the normally closed switch 153 to junction 258 and line 259 toajunction 261 on Board 04 (FIG. 13) for being applied through a gate toa respective tube. lt will be remembered that Gate 06 was the last andonly Gate open when the digit 1 of the command number 321 was put intotube 105.

Thus with the command number 321 set into the counter tubes 103, 104 and105, the pulses coming through line 259 are directed through junction261, line 262 to Gate 06, and through line 164a for Gate 06 to andthrough the one-shot multivibrator and line 1660 to tube 105. Each pulsecauses the glow in tube to move from 1, 1 having been set therein, to Oto 9, whereupon the counter circuit causes the glow in tube 104 to movefrom 2, 2 having been set therein, to 1. Tube 105 continues to countdown. This action continues, with each time the glow transferring fromto 9 in a tube resulting in the tube to the left thereof losing a digit,until all tubes 103, 104 and 105 reach zero. A mechanical counterpart ofthis electronic count down arrangement is found in a Veeder-Roottypecounter running backwards.

When the counter 51 (FIG. 13) reaches zero, it sends a signal outthrough line 263 (FIG. to the control bistable 168. The signal effects aremoval of the 24v supply for the pulse generator 171, which then stopssuch that no more pulses are sent to the Translator 48. Secondly, a 24vpulse is delivered through line 264, junction 266, line 267, junction268, and line 269 to the binary counter distributor circuit 158 (FIG.13). This causes all the Gates, 4-9 inclusive, to close, andsimultaneously, using line 2631: (FIG. 11) starts the tape reader 44.

The same pulse is forwarded through lines 173 to trip the bistables 174,and therefore closing all Gates 183-190, readying the Gate circuitry forthe next command. A pulse is also sent from the control bistable 168through line 264, junction 266, line 176, to the low side of the pulserate control bistable 177. This leaves the bistable 177 in the low ratecondition for the next numbers command, as described hereinbefore. Thedesired line segment of 321 0.002 inch increments has now beencompleted, and the tape transport 44 is again running.

Assume the next command results in a direction B passed through theparity Board 06 and decoded at Board 01, then sent through line 11%(FIG. 14) to the amplifier 206b. The pulse is then again routed the twopaths through the line 208b to the right side of the AND" Gate 201b; andalso through the path of the emitter follower 207b, line 209b, diode211b, line 212b, and to junction 213b. At the AND Gate 201b, the signalis stopped because no signal is present on line 197b, as no numbercommand preceded the direction command B.

From the junction 213b, the signal is directed through a pair of diodes271 and 272, wherein pulses are transmitted through lines 216 and 273through the resistances 218 and 219 for line 216, and 274 and 276 forline 273, to both Translators 47 and 48. Thus, both motors are steppedone pulse, resulting in the pen 68 moving left and out simultaneouslysuch that a 45 diagonal line, the lengthof which is equivalent to twotimes the square root of 0.002 inch squared, is drawn. The motors stopagain until the next command.

Although a preferred embodiment of the invention has been describedhereinbefore, it is to be remembered that various modifications andalterations can be made thereto without departing from the true spiritand scope of the invention as defined by the appended claims.

We claim:

1. Electrical pulse counter apparatus comprising:

counter means, initially containing zero, for accepting a number in theform of a sequence of digits with the most significant digit first andwith the units digit last, each nonzero digit loaded into said countermeans by a series of first pulses equaling 10 minus the digit value, thedigit zero requiring no pulses;

distributor means for loading said counter means including for eachdigit a normally closed distributor gate leading into said countermeans, the distributor gate utlilized to load the last digit being theunits gate;

means for generating a string ofsecond pulses;

means for transmitting said second pulses to said counter means throughsaid distributor means units gate;

said counter means operable to decrement from said number to zero inresponse to receiving said second pulses, and operable further to emit asignal when the number being decremented reaches zero;

said distributor means includes a distributor counter circuit forcounting the number of digits received by the counter apparatus, saiddistributor counter circuit including further an AND gate for eachdistributor gate, said distributor counter circuit operable to emit aplurality of combinations of signals to said AND" gates, each AND gateresponding to one of said combinations of signals to open the associateddistributor gate to pass said series of first pulses into said countermeans, said distributor counter circuit upon receiving a signal for eachdigit of said number being incremented thereby emitting the combinationof signals corresponding to the current digit count, actuating theappropriate AND gate and thereby opening the associated distributorgate.

2. Electric pulse counter apparatus as defined in claim 1, and includingmeans comprising a plurality of bistable multivibrators arranged toreceive a digit and to emit a sequence of pulses the number of which isone greater than the said series of first pulses required for the digitreceived, said emitted pulses transmitted to said distributor means,said distributor means operable to receive said augmented pulse series,using the additional pulse to increment said distributor countercircuit.

3. Electric pulse counter apparatus as defined in claim 1, and whereinsaid pulse generating means for said second pulses comprises an astablemultivibrator actuated in response to a signal upon the loading of thefirst digit of said number into said counter means, said multivibratoroperable to cease generating said second pulses in response to saidsignal from said counter means emitted therefrom when the number isdecremented to 0.

4. An electric pulse counting means comprising:

counter means having a plurality of digit display means operable byapplication of electric pulses, said display means being arranged todisplay in order digits of a preset number from the most significantdigit to the least significant digit, each of said display meansinitially displaying the digit 0;

a pulse generating means;

a distributor having a normally nonconductive gate connected betweensaid pulse generating means and each of said display means;

input means connected to said pulse generating means for controllingsaid pulse generating means to cause it to apply to said gates asequence of groups of pulses, each group corresponding to a digit of adesired number to be preset on said display means, said sequence beingapplied in the order from the most significant digit to the leastsignificant digit thereof, the number of pulses for each of said digitsbeing the initial digit minus the desired digit modulo ofthe base numbersystem;

distributor control means connected between said pulse generating meansand said distributor to apply to said distributor a distributor-controlsignal in response to the generation of each of said groups of pulses,said distributor in response to the application of each of saiddistributor-control signals operating to make conductive one of saidgates, the sequence in which said gates are made conductive one at atime during application of said groups of pulses for each of saiddesired numbers being in the order from that one connected to saiddisplay means for displaying the most significant digit to that oneconnected to said display means for displaying the least significantdigit of the number being preset on said counter means, the number ofsaid gates becoming conductive sequentially for a desired number to bepreset being equal to the number of said groups of pulses for saiddesired number; and

each of said digit display means while the respective one of said gatesis conductive being operated decrementally in response to theapplication of a respective one of said groups of pulses.

5. An electric pulse counting means as claimed in claim 4 includingdccremental pulse means for decrementing said counter means, meansresponsive to the termination of the generation of said group of pulsesthat is used for presetting said desired number to connect saiddccremental pulse means to said gates of said distributor, wherebypulses generated by said decremental pulse means in applied through thatone of said gates that has been made conductive for presetting the leastsignificant digit in said counting means, said counter having aborrowing circuit for decrementing said display means in order from thatone used to display the least significant digit of said desired numberto that one used to display the most significant digit of any number tobe preset in said counter

1. Electrical pulse counter apparatus comprising: counter means,initially containing zero, for accepting a number in the form of asequence of digits with the most significant digit first and with theunits digit last, each nonzero digit loaded into said counter means by aseries of first pulses equaling 10 minus the digit value, the digit zerorequiring no pulses; distributor means for loading said counter meansincluding for each digit a normally closed distributor gate leading intosaid counter means, the distributor gate utlilized to load the lastdigit being the units gate; means for generating a string of secondpulses; means for transmitting said second pulses to said counter meansthrough said distributor means units gate; said counter means operableto decrement from said number to zero in response to receiving saidsecond pulses, and operable further to emit a signal when the numberbeing decremented reaches zero; said distributor means includes adistributor counter circuit for counting the number of digits receivedby the counter apparatus, said distributor counter circuit includingfurther an ''''AND'''' gate for each distributor gate, said distributorcounter circuit operable to emit a plurality of combinations of signalsto said ''''AND'''' gates, each ''''AND'''' gate responding to one ofsaid combinations of signals to open the associated distributor gate topass said series of first pulses into said counter means, saiddistributor counter circuit upon receiving a signal for each digit ofsaid number being incremented thereby emitting the combination ofsignals corresponding to the current digit count, actuating theappropriate ''''AND'''' gate and thereby opening the associateddistributor gate.
 2. Electric pulse counter apparatus as defined inclaim 1, and including means comprising a plurality of bisTablemultivibrators arranged to receive a digit and to emit a sequence ofpulses the number of which is one greater than the said series of firstpulses required for the digit received, said emitted pulses transmittedto said distributor means, said distributor means operable to receivesaid augmented pulse series, using the additional pulse to incrementsaid distributor counter circuit.
 3. Electric pulse counter apparatus asdefined in claim 1, and wherein said pulse generating means for saidsecond pulses comprises an astable multivibrator actuated in response toa signal upon the loading of the first digit of said number into saidcounter means, said multivibrator operable to cease generating saidsecond pulses in response to said signal from said counter means emittedtherefrom when the number is decremented to
 0. 4. An electric pulsecounting means comprising: counter means having a plurality of digitdisplay means operable by application of electric pulses, said displaymeans being arranged to display in order digits of a preset number fromthe most significant digit to the least significant digit, each of saiddisplay means initially displaying the digit 0; a pulse generatingmeans; a distributor having a normally nonconductive gate connectedbetween said pulse generating means and each of said display means;input means connected to said pulse generating means for controllingsaid pulse generating means to cause it to apply to said gates asequence of groups of pulses, each group corresponding to a digit of adesired number to be preset on said display means, said sequence beingapplied in the order from the most significant digit to the leastsignificant digit thereof, the number of pulses for each of said digitsbeing the initial digit minus the desired digit modulo of the basenumber system; distributor control means connected between said pulsegenerating means and said distributor to apply to said distributor adistributor-control signal in response to the generation of each of saidgroups of pulses, said distributor in response to the application ofeach of said distributor-control signals operating to make conductiveone of said gates, the sequence in which said gates are made conductiveone at a time during application of said groups of pulses for each ofsaid desired numbers being in the order from that one connected to saiddisplay means for displaying the most significant digit to that oneconnected to said display means for displaying the least significantdigit of the number being preset on said counter means, the number ofsaid gates becoming conductive sequentially for a desired number to bepreset being equal to the number of said groups of pulses for saiddesired number; and each of said digit display means while therespective one of said gates is conductive being operated decrementallyin response to the application of a respective one of said groups ofpulses.
 5. An electric pulse counting means as claimed in claim 4including decremental pulse means for decrementing said counter means,means responsive to the termination of the generation of said groups ofpulses that is used for presetting said desired number to connect saiddecremental pulse means to said gates of said distributor, wherebypulses generated by said decremental pulse means in applied through thatone of said gates that has been made conductive for presetting the leastsignificant digit in said counting means, said counter having aborrowing circuit for decrementing said display means in order from thatone used to display the least significant digit of said desired numberto that one used to display the most significant digit of any number tobe preset in said counter means; and disabling means connected to saidpulse generating means and to said borrowing circuit, said disablingmeans operating in response to generation of pulses by said pulsegenerating means for presetting said desired number to inhibit theoperation of said borrowing circuit.